[gall]

The distinction between comments and link titles feels a little false because there's no obligation to link to the root of the primary source document chain, if there even is a canonical primary source for a given story. A submitter could legitimately wrap a link in a thin blog post on their own site and achieve the same effect.

[anigbrowl]

Actually, there is such an obligation (or at least, submitters are strongly encouraged to do this in the guidelines). But this is widely ignored, and a distressingly high percentage of submissions are just blog churnalism.